Occupied Roof and Story Combined?

[Blazer]

My code approach is to call the fifth story addition a story which only takes up a third of the existing roof of a four story building. The existing roof was an occupied roof previously but the plans to alter the building included an addition of bathrooms to the occupied roof and a lounge while also extending the elevator to it. The outdoor space is increased in size but since enclosing occupied space I now have an added story (5th) for the enclosed portion. Since construction is III-A and sprinklered Table 504.4 (IBC 2018) limits the office building (Mixed-Use Separated with Groups A-3 and B) to six stories and the occupied roof can be Assembly if permitted in the story below which is capped at four stories by Table 504.4

My code official accepted the enclosed lounge and bathrooms as Business and not Assembly if not more than 750 SF and less than 50, but indicates the outdoor space is not an occupied roof, but is considered a story even though its on the roof of the fourth story. As far as I'm concerned they have not provided code section that prohibit an occupied roof and a story at the same elevation. The plans do indicate a structure for solar panels that is elevated high enough off the roof that occupants can occupy the space underneath so they said solar panels make it a roof so the roof below it becomes a story. Even if removing the solar panels and its structure they wont consider it an occupied roof with Assembly occupancy.

Does my occupied roof now become a story when completely outdoors and on top of a roof? I thought story was defined as distance between floor below and floor/roof above. I have never come across a floor that has roof drains before, LOL. Let me know if I'm wrong to assume the two can exist at the same elevation.

 

[steveray]

Which code do you use? If the solar panels are acting like a roof, it is definitely a story....

503.1.4​

A roof level or portion thereof shall be permitted to be used as an occupied roof provided the occupancy of the roof is an occupancy that is permitted by Table 504.4 for the storyimmediately below the roof. The area of the occupied roofs shall not be included in the building area as regulated by Section 506. An occupied roof shall not be included in the building height or number of stories as regulated by Section 504, provided that the penthousesand other enclosed rooftop structurescomply with Section 1511.

Exceptions:

1. 1.The occupancy located on an occupied roof shall not be limited to the occupancies allowed on the story immediately below the roof where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and occupant notification in accordance with Sections 907.5.2.1 and 907.5.2.3 is provided in the area of the occupied roof. Emergency voice/alarm communication system notification per Section 907.5.2.2 shall also be provided in the area of the occupied roof where such system is required elsewhere in the building.
2. 2.Assembly occupancies shall be permitted on roofs of open parking spaces of Type I or Type II construction, in accordance with the exception to Section 903.2.1.6.

503.1.4.1​

Elements or structures enclosing the occupied roof areas shall not extend more than 48 inches (1220 mm) above the surface of the occupied roof.

Exceptionenthousesconstructed in accordance with Section 1511.2 and towers, domes, spires and cupolas constructed in accordance with Section 1511.5.


ICC is definitely messing with the cut and paste to protect their IP......

 

[Blazer]

503.1.4.1​

Elements or structures enclosing the occupied roof areas shall not extend more than 48 inches (1220 mm) above the surface of the occupied roof.

Yes I'm aware of this code section. My argument is that the occupied roof is not enclosed if I have parapet on three of the four sides. The building is on the corner of the street so fire department can access the roof from either street without climbing over anything more than 4ft high so they don't have any obstacles as mentioned in the commentary of 503.1.4.1

 

[walker.t]

the outdoor space is not an occupied roof, but is considered a story even though its on the roof of the fourth story.

Assuming the fifth story lounge/bathroom/elevator has access to the rooftop deck, I would agree that the rooftop deck is a story and not an occupied roof with or without solar panels.

Does my occupied roof now become a story when completely outdoors and on top of a roof?

I think it becomes a story because of a physical connection with an element that is unquestionably a story (the lounge/bathroom/elevator addition.)

I thought story was defined as distance between floor below and floor/roof above.

You do have a roof above - the roof of the lounge/bathroom/elevator addition which opens to the rooftop deck - the roof just doesn’t extend across the entire story.

Let me know if I'm wrong to assume the two can exist at the same elevation.

I would think that as long as the occupied roof and story were not connected that it would probably be OK but I don’t have a code provision to back that up.

 

[Blazer]

You do have a roof above - the roof of the lounge/bathroom/elevator addition which opens to the rooftop deck - the roof just doesn’t extend across the entire story.

This is probably the explanation that best describes the situation and unfortunately I have to agree with. I just thought maybe I could use the lack of specific code language to manipulate the general language to work for the design teams visions.
I really have to thank you for the input and advice.

 

[walker.t]

I really have to thank you for the input and advice.

You’re welcome.